Bug in my salad! Insufficient compensation and poor handling of the situation...I wouldn't go there if I were you...

I'm not new to China, so while I am extremely unhappy about the situation that happened today, I am not surprised in any way. I was in a group of 3, and about 10 minutes after my friend's meals came and they started eating (my food did not come), I started to hear 3 waitresses arguing about who was responsible for forgetting to enter my food order into the system. After 10 minutes of arguing, they bring me out a salad (I had ordered a pork and mushroom dish - number 88 on the menu). Ten minutes later (about 40 minutes after we had originally ordered), I tell them that it's too late and I don't want my food anymore, but sure enough soon after that they brought out my food. I told the manager that because I waited about 40 minutes for my food, I would only eat it if it was for free. She thought about it and then decided not to give it to me, and proceeded to take the food away. She'd rather waste my meal and throw it away than give it to me for free. As I'm finishing my salad, I notice that something in the salad is moving - and sure enough it was a little caterpillar, which was very visible. We called over the manager who offered us a 10% discount. We argued with her and told her that we did not want to pay any money for the food, but that my friends would pay for the beer they ordered. She wouldn't accept that, and then continued to argue with us for about 5 minutes longer. We refused to budge and then she went to the cash register and looked at it for a long time, talked with her fellow co-workers, and didn't come back to our table for a while. Eventually my friends went up to her and offered to pay about 75% of the bill. We walked out of there in disgust...I will not be going back there for a very long time. My co-workers and I are good customers of this place and go there often, but not anymore...